JP5393517B2 - Extreme ultraviolet light source device - Google Patents

Description

  The present invention relates to an extreme ultraviolet light source device.

  For example, a semiconductor chip is generated by reducing and projecting a mask on which a circuit pattern is drawn on a resist-coated wafer and repeating processes such as etching and thin film formation. With the miniaturization of semiconductor processes, light having a shorter wavelength is required.

  Therefore, a semiconductor exposure technique using light with an extremely short wavelength of 13.5 nm and a reduction optical system has been studied. This technique is called EUVL (Extreme Ultra Violet Lithography). Hereinafter, extreme ultraviolet light is referred to as EUV light.

  As the EUV light source, for example, three types of light sources of LPP (Laser Produced Plasma) type, DPP (Discharge Produced Plasma) type, and SR (Synchrotron Radiation) type are known. .

  The LPP-type light source is a light source that generates plasma by irradiating a target material with laser light and uses EUV light emitted from the plasma. The DPP type light source is a light source that uses plasma generated by discharge. The SR type light source is a light source that uses orbital radiation.

  Among the above three types of light sources, the LPP type light source can increase the plasma density and can increase the collection solid angle as compared with other methods, so that there is a possibility that high output EUV light can be obtained. High (Patent Document 1).

  In the LPP type EUV light source device, tin (Sn) is used as a target material. The LPP-type EUV light source device includes a target generation unit, which heats and melts tin and ejects it as droplets from a thin nozzle.

  When the droplet reaches a predetermined point, the droplet is irradiated with driver laser light to be turned into plasma, and EUV light is generated. The droplets that have not been irradiated with the driver laser light and have not been turned into plasma are jumped into a collection device provided on the trajectory on which the droplets fly and collected (Patent Document 2).

  As a conventional technique of a DPP type light source, a technique is known in which an EUV light source device is disposed obliquely with respect to gravity and EUV light is output obliquely from below (Patent Document 3).

JP 2006-80255 A US Pat. No. 7,476,886 US Patent Application Publication No. 2006/146413

  Since the EUV light has a very short wavelength, even if a reflection mirror having a special thin film is used, the reflectance is as low as about 60%. Accordingly, it has been proposed to arrange the EUV light source device so as to look up obliquely from below and reduce the number of times EUV light is reflected. However, if the EUV light source device is disposed obliquely, the target generation unit is positioned on the collector mirror, and thus the droplet may fall and adhere to the surface of the collector mirror. In particular, immediately after starting the ejection of the droplet, the speed of the droplet is slow, so there is a possibility that the droplet falls on and adheres to the collector mirror and contaminates the collector mirror. Further, when the droplet ejection is terminated, the droplet speed is reduced, which may cause a similar problem.

  The present invention has been made paying attention to the above problem, and its purpose is to provide an extreme ultraviolet light source device capable of suppressing adhesion of a target to a condensing mirror when the target generation unit is in a predetermined state. It is to provide. Further objects of the present invention will become clear from the description of the embodiments described later.

  In order to solve the above problems, an extreme ultraviolet light source device of the present invention includes a chamber, a target generation unit that generates a target from a target material, and outputs the generated target in a predetermined direction in the chamber, and a target in the chamber A laser light source that generates extreme ultraviolet light by irradiating a laser beam onto the laser beam and a target generator located below the target generator, on the vertical line of the output port for the target generator to output the target And a condensing mirror for collecting extreme ultraviolet light at a predetermined focal point.

  Furthermore, the extreme ultraviolet light source device of the present invention includes a recovery unit that recovers the target so that the target output from the target generation unit does not adhere to the condenser mirror when the target generation unit is in a predetermined state.

  Here, examples of the predetermined state include at least one of an operation start state in which the target generating unit starts operating and an operation stop state in which the target generating unit stops operating.

  The collection unit can be disposed between the target generation unit and the condenser mirror in a fixed or movable manner. When fixing the collection unit, for example, the collection unit is arranged by selecting an area that does not affect generation and collection of EUV light. As such a region, for example, a region that is not used by the exposure apparatus (so-called obscuration region) can be selected.

  When the collection unit is provided to be movable (or deformable), for example, the collection unit can be arranged to be switchable between the first position and the second position. The first position is a position for collecting the target output from the target generator. The second position is a position that is set apart from the first position and does not interfere with the target emitted from the target generation unit. The recovery unit is positioned at the first position when the target generation unit is in a predetermined state, and is positioned at the second position when the target generation unit is in a state other than the predetermined state.

  ADVANTAGE OF THE INVENTION According to this invention, it can suppress that the target output from a target generation part falls and adheres to a condensing mirror. Thereby, it can suppress that the reflectance of a condensing mirror falls, and can reduce the reliability and operating cost of an extreme ultraviolet light source device.

The block diagram of the extreme ultraviolet light source device which concerns on 1st Example. The figure which expands and shows a target generation | occurrence | production part and a condensing mirror. The flowchart which shows the process which controls the catcher for collect | recovering droplets. The flowchart which shows the content of the subroutine in FIG. Sectional drawing of the target generation | occurrence | production part which concerns on 2nd Example. Sectional drawing which shows the relationship between the target generation | occurrence | production part and condensing mirror which concern on 3rd Example. Sectional drawing which shows the relationship between the target generation | occurrence | production part and condensing mirror which concern on 4th Example. Sectional drawing which shows the relationship between the target generation | occurrence | production part and condensing mirror which concern on 5th Example. Sectional drawing which shows the relationship between the target generation | occurrence | production part and condensing mirror which concern on 6th Example. Sectional drawing which shows the relationship between the target generation | occurrence | production part and condensing mirror which concern on 7th Example. The flowchart of the process which collect | recovers a droplet. Sectional drawing which shows the relationship between the target generation | occurrence | production part and condensing mirror which concern on 8th Example. Sectional drawing of the target generation | occurrence | production part which concerns on 9th Example. The block diagram of the extreme ultraviolet light source device which concerns on 10th Example. The figure which expands and shows the positional relationship of a catcher and a condensing mirror. The figure which shows the relationship between an obscuration and a catcher.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the present embodiment, as described below, the collecting mirror 130 is protected by collecting droplets emitted from the target generation unit 120 before the steady operation state is reached. As a droplet collection method, there are a method in which a catcher 160 for collecting droplets is movably or fixedly provided, and a method in which a target generator 120 is movably provided. Furthermore, when the catcher 160 is fixedly provided, there is a method of arranging it in the obscuration region.

  A first embodiment will be described with reference to FIGS. Note that FIG. 5 is also referred to in order to explain the details of the target generation unit 120. FIG. 1 is an explanatory diagram showing the overall configuration of the EUV light source apparatus 1. The EUV light source device 1 includes, for example, a chamber 100, a driver laser light source 110, a target generation unit 120, an EUV collector mirror 130, a collection device 140, reflection mirrors 151 and 152, a catcher 160, and a camera 170. EUV controller 200 and catcher actuator 210. Arrow G indicates the direction of gravity. Hereinafter, the EUV collector mirror is abbreviated as a collector mirror. Similarly, an EUV controller is abbreviated as a controller.

  Here, the EUV light source device 1, the chamber 100, the driver laser light source 110, the target generation unit 120, the collection mirror 130, the collection device 140, the reflection mirror 151, the other reflection mirror 152, the catcher 160, the controller 200, and the catcher actuator 210 are Each is provided one by one, and will be described as singular in the following description. The droplets 310 are described as singular or plural. The droplets 310 ejected from the target generator 120 are described as plural forms. The droplet 310 irradiated with the driver laser beam L1 can be described as a singular form. Debris is described as singular or plural. Although one camera 170 is shown in FIG. 1, droplets and EUV light emission may be observed with a plurality of cameras. Accordingly, the camera 170 is described as singular or plural.

  The chamber 100 is a sealed container, and the inside thereof is kept at a vacuum or a low pressure. The chamber 100 is provided with one connection portion 101 for connecting to the exposure apparatus 2. In the drawing, for convenience, the exposure apparatus 2 and the chamber 100 are shown separately, but in practice, the exposure apparatus 2 and the chamber 100 are connected via the connection portion 101.

  The connecting part 101 is also maintained at a vacuum or low pressure. By setting the pressure in the chamber 100 to be lower than the pressure in the connection unit 101, it is possible to suppress foreign matters such as debris in the chamber 100 from flowing into the exposure apparatus 2 through the connection unit 101. In the connection unit 101, an intermediate focusing point (IF) is set. EUV light L2, which will be described later, is collected at the IF and then sent to the exposure apparatus 2.

  The target generator 120 is a device that injects the droplet 310 into the chamber 100 by heating and dissolving the target material 300 (see FIG. 5) such as tin (Sn), for example. The droplet 310 corresponds to a “target”.

  As illustrated in FIG. 5, the target generation unit 120 includes, for example, one nozzle unit 121, one tank unit 122, one vibration unit 123, and one heating unit 124. A target material 300 such as tin is supplied to the tank portion 122 from a supply port (not shown). The heating unit 124 provided outside the tank unit 122 heats the tin in the tank unit 122 to bring it into a molten state.

  For example, an argon gas (not shown) is supplied to the tank unit 122 to pressurize the molten target material 300 in the tank unit 122. The argon gas is used to inject the molten target material 300 from the nozzle part 121. By applying vibration from the vibration unit 123 to the target material 300 ejected as a jet flow from the nozzle unit 121, a droplet 310 is generated.

  The target generator 120 can be entirely composed of the same substrate. That is, the tank part 122 and the nozzle part 121 can be formed of the same material. Examples of the base material of the target generation unit 120 include materials such as molybdenum, titanium, tungsten, diamond, metal nitride, carbide, alumina ceramics, carbon graphite, quartz, and crystals mainly composed of alumina. These materials have corrosion resistance, corrosion resistance, pressure resistance, and heat resistance against tin. Examples of crystals mainly composed of alumina include crystals such as ruby and sapphire. However, it is not limited to only the same material, You may comprise the target generating part 120 combining said material.

  Particles are generated from the tank part 122 and the nozzle part 121 for the following two reasons. One reason is that the tank part 122 and the nozzle part 121 are physically contacted with molten tin (target material 300) and scraped. Another reason is that the impurities contained in the material of the tank part 122 or the impurities contained in the material of the nozzle part 121 and tin react chemically to generate insoluble matter in the molten tin. Therefore, in this embodiment, in order to suppress generation of one or a plurality of particles in the tank part 122 or the nozzle part 121, the inner surface of the tank part 122 and the inner surface of the nozzle part 121 have a predetermined surface roughness. So that it is polished.

  The predetermined surface roughness is set to 1/10 or less or 1/100 or less of the nozzle diameter. For example, when the diameter of the nozzle part 121 is 10 μm, the surface is polished so that the surface roughness is 1 μm or less. Thereby, even when a particle generate | occur | produces from the surface of a base material by contact with tin, it can suppress that the nozzle part 121 is blocked.

  The driver laser light source 110 outputs a laser beam L1 for exciting the droplet 310 supplied from the target generator 120. Hereinafter, the laser light output from the driver laser light source 110 is referred to as laser light L1 or driver laser light L1.

  The driver laser light source 110 is configured as, for example, a CO2 (carbon dioxide gas) pulse laser light source. The driver laser light source 110 emits laser light L1 having specifications of, for example, a wavelength of 10.6 μm, an output of 20 kW, a pulse repetition frequency of 100 kHz, and a pulse width of 20 nsec. In addition, although a CO2 pulse laser is mentioned as an example as a laser light source, this invention is not limited to this. For example, a high output pulse laser such as YAG may be used. Furthermore, the structure which irradiates a droplet with a different kind of laser beam simultaneously may be sufficient.

  The laser light L1 output from the driver laser light source 110 enters the chamber 100 via the reflection mirror 151 and the incident window 102. Further, the laser beam L 1 is reflected by the off-axis parabolic mirror 152, passes through the incident hole 131 (see FIG. 2) provided in the condensing mirror 130, and irradiates the droplet 310.

  When the droplet 310 is irradiated with the laser light L1, the droplet 310 is changed into plasma 320 and emits EUV light L2. The EUV light L2 emitted from the plasma 320 is incident on the surface 132 (see FIG. 2) of the collector mirror 130 and reflected. The EUV light L2 reflected by the condensing mirror 130 is condensed at an intermediate condensing point (IF). The EUV light L2 condensed on the IF is supplied to the exposure apparatus 2 via the connection unit 101.

  Of the many droplets 310 emitted from the target generator 120, the unused droplets 310 (unused targets) that have not been irradiated with the driver laser light L1 are collected by the collection device 140.

  For example, the repetition frequency of the driver laser beam L1 may not match the frequency for stably generating the droplet 310 having a desired diameter. In this case, the generation frequency of the droplet 310 is set to an integral multiple of the repetition frequency of the driver laser light L1. As a result, the generation of the droplet 310 and the irradiation with the driver laser light L1 are synchronized.

  For example, when the 100 kHz driver laser light L1 is irradiated onto the φ310 μm droplet 310, the target generation frequency is 1-2 kHz. In this case, 90% or more of the plurality of droplets 310 ejected from the target generation unit 120 are not irradiated with the driver laser light L1 and become unused droplets.

  Therefore, in this embodiment, a collection device 140 is provided at the bottom of the chamber 100 so as to face the target generation unit 120, and unused droplets are collected. That is, the recovery device 140 is provided on the flight path of the droplet 310 ejected from the target generator 120 in the steady operation state. The collected droplets 310 can be reused.

  The catcher 160 as a “collection unit” is located between the target generation unit 120 and the condenser mirror 130 and is movably provided. The catcher 160 is moved between a first position P1 indicated by a solid line and a second position P2 indicated by a dotted line (both see FIG. 2) by a catcher actuator 210 such as an ultrasonic motor or a magnetostrictive element.

  For example, the catcher 160 can be provided with a heater for heating the accommodated droplet 310 and a discharge pipe (none of which is shown) for discharging the droplet 310. The droplets 310 collected by the catcher 160 can be reused together with the droplets 310 collected by the collection device 140.

  Since the catcher 160 is a device that receives and collects the droplet 310, it can also be called a droplet catcher or a capturing unit. Since the catcher 160 is a means for suppressing the collection mirror 130 from being contaminated by the target material 300, the catcher 160 can also be referred to as a collection mirror protection unit.

  Please refer to FIG. FIG. 2 is an explanatory diagram schematically showing the relationship between the catcher 160, the target generator 120, and the condenser mirror 130. FIG. 2A shows an arrangement relationship in at least one of the cases when the operation of the target generator 120 is started or when the operation of the target generator 120 is stopped. C1 in the figure indicates the direction in which the droplet 310 is ejected from the nozzle unit 121 when the target generator 120 is in a steady operation state. C1 is a direction toward the plasma generation point.

  In the case of FIG. 2A, the catcher 160 moves directly below the nozzle part 121. The position P1 directly below the nozzle portion 121 corresponds to a “first position”. The catcher 160 that has moved to the first position P1 receives and collects the droplet 310 that falls off the predetermined track (C1). Before the target generator 120 reaches the steady operation state, the speed of the droplet 310 is lower than the normal speed, so that the gravity G deviates from a predetermined trajectory.

  FIG. 2B shows an arrangement relationship when the target generation unit 120 shifts from the operation start state to the steady operation state, or when the target generation unit 120 completely stops operating. In the case of FIG. 2B, the catcher 160 moves to a position P <b> 2 set at a location away from just below the nozzle part 121. The position P2 corresponds to a “second position”. For example, the second position P2 is set to a position that does not affect generation and collection of EUV light. In FIG. 2, the second position P <b> 2 is provided on the rear side of the nozzle portion 121.

  In the steady operation state where the catcher 160 is retracted to the second position P2, the droplet 310 ejected from the nozzle part 121 of the target generator 120 flies in the C1 direction at a normal speed. The droplet 310 is irradiated with the driver laser light L1 at the plasma generation point to become plasma 320, and generates EUV light L2.

  The first position P1 can be called a collection position, and the second position P2 can be called a retracted position. The state illustrated in FIG. 2A can be referred to as a recovery mode or a collecting mirror protection mode, and the state illustrated in FIG. 2B can be referred to as a retract mode or a normal mode.

  FIG. 3 is a flowchart showing a process for controlling the operation of the catcher 160. The controller 200 determines whether or not the target generator 120 has started operation (S10). For example, the controller 200 determines whether or not an operation start sequence for starting the operation of the target generation unit 120 has been activated based on the operation of the operation switch.

  The operation start sequence executes a series of operations for injecting the droplet 310. For example, in the operation start sequence, the target material 300 is heated and melted by the heating unit 124, argon gas is sent into the tank unit 122, and the vibrating unit 123 is vibrated to inject the droplet 310.

  When the operation start sequence is activated (S10: YES), the controller 200 executes a catching subroutine for collecting the droplets 310 (S11). The contents of the catch subroutine will be described later.

  Based on the signal from the camera 170, the controller 200 determines whether or not the operation of the target generator 120 has entered a steady operation state (S12). For example, the controller 200 can determine whether or not the target generation unit 120 is in a steady operation state by measuring the speed and direction of the droplet 310 ejected from the nozzle unit 121 with the camera 170.

  In the state immediately after the start of operation before reaching the steady operation state, the speed of the droplet 310 is slower than the speed during the steady operation. Further, since the speed is low, the moving direction of the droplet 310 is also strongly influenced by gravity and deviates from the direction (C1) in the steady operation state. Therefore, by measuring the speed and moving direction of the droplet 310 with the camera 170, it can be determined whether or not the target generator 120 has reached a steady operation state. Note that other sensors may be used instead of the measurement by the camera 170.

  The controller 200 waits until the target generation unit 120 is in a steady operation state (S12: YES). When the target generator 120 is in a steady operation state, the controller 200 executes a cancellation subroutine for canceling the collection of the droplets 310 (S13). The contents of the cancellation subroutine will be described later.

  The controller 200 determines whether or not a stop sequence for stopping the operation of the target generator 120 has been activated (S14). For example, when an operation stop switch is operated, or when an operation stop command is input from the exposure apparatus 2, the controller 200 starts a stop sequence.

  When the stop sequence is activated, the controller 200 executes the catch subroutine again (S15). After executing the catch subroutine, the controller 200 confirms that the operation of the target generator 120 is stopped (S16: YES), and returns to S10.

  The controller 200 moves the catcher 160 to the first position P1 when the operation of the target generator 120 starts and stops, and causes the catcher 160 to collect a relatively low-speed droplet 310 that is injected or dropped from the target generator 120. .

  FIG. 4 is a flowchart showing the catching subroutines S11 and S15 and the canceling subroutine S13. In order to distinguish from other embodiments described later, in FIG. 4, “S11A, S15A” and “S13A” are added by adding “A” to the symbols “S11, S15” and “S13”.

  In the catching subroutines 11A and S15A, as shown in FIG. 2A, the catcher 160 is moved to the first position P1 set almost directly below the nozzle part 121 (S110A). Thereby, even if the slow droplet 310 is dropped or ejected from the nozzle part 121, the catcher 160 can receive and collect the droplet 310.

  In the release subroutine 13A, as shown in FIG. 2B, the catcher 160 is retracted to the second position P2 (S130A). The second position P2 is set at a location away from the nozzle part 121 so as not to interfere with the droplet 310 ejected from the nozzle part 121. As a result, the target generation unit 120 outputs a predetermined amount of droplets 310 at predetermined intervals toward the plasma generation point.

  In this embodiment configured as described above, the catcher 160 is moved to the lower side of the nozzle unit 121 both when the operation of the target generator 120 is started and when the operation is stopped. As a result, the catcher 160 can output the relatively low-speed droplet 310 that can be output from the nozzle unit 121 in both the period from the start of operation until reaching the steady operation state and the period from the steady operation state to the complete stop. Can be recovered. Therefore, the droplet 310 can be prevented from dropping and adhering to the surface 132 of the condenser mirror 130. For this reason, the EUV light source device 1 of the present embodiment can prevent the reliability and the reflectance of the EUV collector mirror from decreasing.

  The second embodiment will be described below with reference to FIG. Each embodiment described below corresponds to a modification of the first embodiment. Therefore, the difference from the first embodiment will be mainly described. In the present embodiment, the catcher 160A is provided so as to be rotatable within a predetermined range, like a pendulum, separated from the nozzle portion 121 of the target generator 120.

  FIG. 5 is a cross-sectional view showing the target generator 120 and the catcher 160A according to this embodiment. A catcher 160 </ b> A is provided on the front end side of the target generation unit 120 arranged at an angle so as to be separated from the nozzle unit 121. The catcher 160A is provided so as to be able to rotate between the first position P1 and the second position P2 around a rotation point RC provided in the target generator 120.

  The controller 200 positions the catcher 160A at the first position P1 when the operation of the target generator 120 starts and ends. Accordingly, the catcher 160A collects the droplet 310 that is injected or dropped from the nozzle portion 121.

  When the target generator 120 is in a steady operation state, the controller 200 positions the catcher 160A at the second position P2. As a result, the catcher 160 </ b> A retreats to a position that does not interfere with the flight of the normal speed droplet 310. In FIG. 5, the second position P2 is set on the right side of the first position P1, but the second position P2 may be set on the left side of the first position P1, contrary to the arrangement. Configuring this embodiment like this also achieves the same effects as the first embodiment.

  A third embodiment will be described with reference to FIG. In this embodiment, the catcher 160B is slid in front of the nozzle part 121. In the first embodiment, the catcher 160 is provided so as to be movable on a plane perpendicular to the vertical line (gravity direction G) from the nozzle portion 121. The catcher 160 </ b> B of the present embodiment is provided so as to be movable in parallel with the tip surface of the nozzle part 121.

  Similar to the embodiment, the controller 200 positions the catcher 160B at the first position P1 when the target generator 120 starts and ends. Then, when the target generator 120 is in a steady operation state, the controller 200 retracts the catcher 160B to the second position P2.

  In FIG. 6, the second position P2 is set to the diagonally upper right of the first position P1, but the second position P2 may be set to the diagonally lower left of the first position P1, contrary to the arrangement. . Configuring this embodiment like this also achieves the same effects as the first embodiment.

  A fourth embodiment will be described with reference to FIG. The catcher 160 </ b> C of the present embodiment is formed as a cover or a cap for covering the nozzle portion 121. The catcher 160 </ b> C is provided so as to be movable in parallel to the tip surface of the nozzle part 121.

  The controller 200 positions the catcher 160B at the first position P1 when the operation of the target generator 120 starts and ends, and covers the nozzle unit 121 with the catcher 160C. When the target generator 120 enters the steady operation state, the controller 200 retracts the catcher 160C to the second position P2 and removes the catcher 160C from the nozzle part 121.

  In FIG. 7, the second position P2 is set to the diagonally upper right of the first position P1, but the second position P2 may be set to the diagonally lower left of the first position P1. Configuring this embodiment like this also achieves the same effects as the first embodiment.

  A fifth embodiment will be described with reference to FIG. FIG. 8A shows an arrangement relationship in a steady operation state. FIG. 8B shows the arrangement relationship when the operation of the target generator 120 starts and ends.

  The catcher 160D of the present embodiment is formed like a pinhole shutter. Catcher 160D is provided so that the front-end | tip of the nozzle part 121 may be covered. The catcher 160 </ b> D is provided to be movable in parallel with the tip surface of the nozzle part 121.

  A pinhole 161D is formed at the center of the catcher 160D. The diameter of the pinhole 161D is set corresponding to the nozzle diameter of the nozzle portion 121 so that the droplet 310 can pass through the pinhole 161D during the steady operation.

  As shown in FIG. 8B, the controller 200 positions the catcher 160D at the first position P1 when the operation of the target generator 120 starts and ends. As a result, the axis (injection direction) of the nozzle part 121 and the axis of the pinhole 161D do not coincide with each other, and the droplet 310 injected from the nozzle part 121 or the target material leaking from the nozzle part 121 is collected in the catcher 160D. Is done.

  As shown in FIG. 8A, the controller 200 retracts the catcher 160D to the second position P2 when the target generator 120 is in a steady operation state. Thereby, the axis line of the nozzle part 121 and the axis line of the pinhole 161D correspond. Accordingly, the droplet 310 ejected from the nozzle part 121 passes through the pinhole 161D and travels toward the plasma generation point.

  Note that the moving direction of the catcher 160D may be set opposite to the direction shown in FIG. That is, in FIG. 8B, the first position P1 may be set in the lower left direction. Configuring this embodiment like this also achieves the same effects as the first embodiment.

  A sixth embodiment will be described with reference to FIG. The catcher 160 </ b> E of this embodiment is fixedly attached directly below the vertical line of the nozzle part 121. Therefore, in this embodiment, the actuator 210 for moving the catcher 160E is not necessary. In the present embodiment, the control process described with reference to FIG. 3 is also unnecessary.

  The catcher 160E is a position that can receive the low-speed droplet 310 that can be generated when the operation of the target generator 120 starts and ends, and does not affect the steady operation of the target generator 120. ,It is attached. The catcher 160E is provided with a discharge pipe (not shown). The droplets 310 accommodated in the catcher 160E can be taken out of the chamber 100 and reused.

  The droplets 310 ejected at the start and end of the operation of the target generator 120 are lower than the normal speed, and thus fall off the normal path C1 and fall into the catcher 160E. On the other hand, the droplet 310 ejected from the target generator 120 in the steady operation state moves along the normal path C1 and is converted into plasma at the plasma generation point.

  Configuring this embodiment like this also achieves the same effects as the first embodiment. Furthermore, in this embodiment, the catcher 160E is provided by utilizing the speed difference of the droplet 310 between the steady operation state and the other states. Therefore, in the present embodiment, the actuator 210 and the like can be eliminated, so that the configuration can be simplified and the manufacturing cost can be reduced as compared with the respective embodiments.

  A seventh embodiment will be described with reference to FIGS. In this embodiment, the catcher 160F is fixed and the target generator 120 is rotated. FIG. 10A shows an arrangement relationship when the target generator 120 is in a steady operation state. FIG. 10B shows a case where the target generator 120 is in an operation start state or an operation end state. FIG. 11 is a flowchart showing a catching subroutine S110B and a canceling subroutine S130B according to this embodiment.

  As shown in FIG. 10A, a catcher 160F is provided at the upper right of the target generator 120 so as not to interfere with the droplet 310 ejected from the target generator 120 during steady operation.

  As shown in FIG. 10B, the controller 200 rotates the target generation unit 120 counterclockwise in the drawing at the start and end of the operation of the target generation unit 120 to direct the nozzle unit 121 toward the catcher 160F. (S110B). Here, the position P3 (angle) at which the nozzle portion 121 faces the catcher 160F corresponds to the “third position”. When the target generation unit 120 is positioned at the third position P3, the droplets 310 ejected from the nozzle unit 121 are collected by the catcher 160F.

  As shown in FIG. 10A, when the target generator 120 is in a steady operation state, the controller 200 rotates the target generator 120 clockwise in the drawing and directs the nozzle 121 in a predetermined direction C1. (S130B). The position P4 (angle) at which the target generator 120 faces the predetermined direction C1 (the direction of the plasma generation point) corresponds to the “fourth position”. When the target generation unit 120 is switched to the fourth position P4, the target generation unit 120 injects the normal speed droplet 310 toward the plasma generation point. Configuring this embodiment like this also achieves the same effects as the first embodiment.

  An eighth embodiment will be described based on FIG. In this embodiment, the catcher 160G is fixed and the target generator 120 is moved in parallel. Like the catcher 160F, the catcher 160G of the present embodiment is provided, for example, obliquely above the target generator 120 so as not to interfere with the droplet 310 ejected from the nozzle unit 121 during the steady operation of the target generator 120. It is done.

  The controller 200 moves the target generator 120 to the third position P3 when the operation of the target generator 120 starts and ends, and causes the nozzle unit 121 to face the catcher 160G.

  When the target generation unit 120 is in a steady operation state, the controller 200 translates the target generation unit 120 to the fourth position P4 and directs the nozzle unit 121 in a predetermined direction C1. Configuring this embodiment like this also achieves the same effects as the first and seventh embodiments.

  A ninth embodiment will be described with reference to FIG. The target generator 120 </ b> A of this embodiment includes a valve mechanism 126 for opening and closing the nozzle portion 121. The valve mechanism 126 includes, for example, a valve body 127 and an actuator 128 that moves the valve body 127 in the vertical direction. On the inlet side of the nozzle part 121, a valve seat 125 is formed for the front end 127A of the valve body 127 to be seated.

  The valve body 127 is formed like a needle valve, for example. The valve body 127 can be formed from the same material as the tank part 122 and the nozzle part 121. For example, when the tank part 122 and the nozzle part 121 are formed from molybdenum, the valve body 127 can also be formed from molybdenum. As described above, the surfaces of the valve body 127 and the valve seat 125 can be polished so as to have a roughness of 1/10 or less or 1/100 or less of the nozzle diameter. A diamond film may be formed on the surfaces of the valve body 127 and the valve seat 125.

  When the target generator 120 is operated, the controller 200 drives the actuator 128 to move the valve element 127 upward. Thereby, the front-end | tip 127A of the valve body 127 leaves | separates from the valve seat 125, and the valve mechanism 126 opens. Then, the droplet 310 is ejected from the nozzle part 121.

  When stopping the target generation unit 120, the controller 200 drives the actuator 128 to move the valve element 127 downward. As a result, the tip 127A of the valve element 127 is seated on the valve seat 125, and the valve mechanism 126 is closed.

  In the present embodiment configured as described above, the target generator 300 is provided with a valve mechanism 126 for opening and closing the nozzle 121, so that the target material 300 leaks from the nozzle 121 when the operation of the target generator 120 is stopped. Can be prevented.

  A tenth embodiment will be described with reference to FIGS. In this embodiment, a catcher 160H is provided in the obscuration region 400 of the EUV light L2. FIG. 14 shows an EUV light source apparatus 1A of the present embodiment. The catcher 160H of the present embodiment is provided slightly apart from the substantially central portion of the condenser mirror 130 in the irradiation direction of the EUV light L2. The catcher 160H is fixedly attached.

  An obscuration region 400 is set at the center of the far field 410 of the EUV light L2 collected by the condenser mirror 130. FIG. 15 is an enlarged view of the chamber 100 and the like. FIG. 16 is a view of the far field 410 as seen from the direction of the arrow XVI in FIG.

  As shown in FIGS. 15 and 16, the catcher 160 </ b> H is arranged in front of the plasma generation point (position 320) so that most of the catcher 160 </ b> H is located in the obscuration region 400. The near side is the near side in the traveling direction of the laser beam L1. Therefore, the catcher 160H is provided between the condensing mirror 130 and the plasma generation point so as to be hidden in the obscuration region 400.

  The catcher 160 </ b> H is provided at a position where the droplet 310 that can be ejected from the nozzle unit 121 can be received when the operation of the target generator 120 is started and stopped, and at a position belonging to the obscuration region 400.

  Here, the obscuration region 400 refers to a region corresponding to an angular range that is not used in the exposure apparatus 2 in the EUV light L2 collected by the EUV collector mirror 130.

The EUV light L2 radiated from the plasma generation point is condensed at the intermediate condensing point IF by the EUV light condensing mirror 130. In this embodiment, a three-dimensional volume region corresponding to an angle range that is not used by the exposure apparatus 2 in the IF is defined as an obscuration region 400. Normally, EUV light in the obscuration region 400 is not used for exposure. Therefore, even if the EUV light L2 in the obscuration region 400 is not input to the exposure apparatus 2, the exposure performance and throughput of the exposure apparatus 2 are not affected.
As shown in FIG. 16, the catcher 160H is disposed slightly tilted with respect to the horizontal line. Thereby, the droplet 310 accommodated in the catcher 160H moves diagonally according to gravity. A collection unit 162H is connected to the catcher 160H via a discharge pipe (not shown). The droplet 310 in the catcher 160H flows into the collection unit 162H and is collected. The target material recovered by the recovery unit 162H can be reused. In addition, the catcher 160H, the collection | recovery part 162H, and the discharge pipeline can be equipped with the heater for keeping the droplet 310 in a molten state.

  Configuring this embodiment like this also achieves the same effects as the first embodiment. Furthermore, in this embodiment, since the catcher 160H is provided in the obscuration region 400 that is not used in the exposure apparatus 2, the EUV light source apparatus 1A does not need to include an actuator, a drive control program, and the like, and the manufacturing cost is reduced. .

  In addition, this invention is not limited to each Example mentioned above. A person skilled in the art can make various additions and modifications within the scope of the present invention. For example, the above embodiments can be appropriately combined.

  1, 1A: EUV light source device, 100: chamber, 102: incident window, 101: connection unit, 110: driver laser light source, 120: target generation unit, 121: nozzle unit, 122: tank unit, 123: vibration unit, 124 : Heating unit, 130: EUV collector mirror, 131: entrance hole, 132: surface, 140: collection device, 151, 152: reflection mirror, 160, 160A, 160B, 160C, 160D, 160E, 160F, 160G, 160H: Catcher, 170: camera, 200: EUV controller, 210: actuator for catcher, 300: target material, 310: droplet, 320: plasma: 400: obscuration region, 410: far field of EUV light, L1: driver laser Light, L2: EUV light P1: first position, P2: second position, P3: third position, P4: fourth position.

Claims (9)

An extreme ultraviolet light source device that generates extreme ultraviolet light by irradiating a target material with laser light,
A chamber;
A target generating unit that generates a target from the target material and outputs the generated target in a predetermined direction in the chamber;
A laser light source for generating the extreme ultraviolet light by irradiating the target in the chamber with a laser beam to form a plasma; and
Located on the lower side of the target generation unit, the target generation unit is provided on a vertical line of an output port for outputting the target, and a collecting mirror for collecting the extreme ultraviolet light at a predetermined focal point;
When the target generator is in a predetermined state, a recovery unit that recovers the target so that the target output from the target generator does not adhere to the condenser mirror;
An extreme ultraviolet light source device.

The extreme ultraviolet light source according to claim 1, wherein the predetermined state is at least one of an operation start state in which the target generation unit starts operation and an operation stop state in which the target generation unit stops operation. apparatus.
The collection unit is switchable between a first position for collecting the target output from the target generation unit and a second position that is set apart from the first position and does not interfere with the target. Provided,
The recovery unit is positioned at the first position when the target generation unit is in the predetermined state, and is positioned at the second position when the target generation unit is in a state other than the predetermined state. The extreme ultraviolet light source device according to claim 2.
The extreme ultraviolet light source device according to claim 3, wherein the recovery unit is provided so as to close the output port when in the first position.
The target generation unit is between a third position for outputting the target toward the recovery unit provided in a direction different from the predetermined direction and a fourth position for outputting the target in the predetermined direction. It is provided to be switchable,
The target generator is positioned at the third position when the target generator is in the predetermined state, and is positioned at the fourth position when the target generator is in a state other than the predetermined state. The extreme ultraviolet light source device according to claim 2.
The recovery unit is located between the output port and the collector mirror, and is provided in a region that does not interfere with the collection of the extreme ultraviolet light by the collector mirror,
The extreme ultraviolet light source device according to claim 2, wherein when the target generation unit is in the predetermined state, the target output from the target generation unit is accommodated in the recovery unit and recovered. .
The collection unit is located below the output port, and is provided in an obscuration region of the condenser mirror,
The extreme ultraviolet light source device according to claim 2, wherein when the target generation unit is in the predetermined state, the target output from the target generation unit is accommodated in the recovery unit and recovered. .
An output state detection unit for detecting an output state of the target output from the target generation unit into the chamber;
The extreme ultraviolet light source device according to claim 2, wherein whether or not the target generation unit is in the predetermined state is determined based on a detection signal from the output state detection unit.
An extreme ultraviolet light source device that generates extreme ultraviolet light by irradiating a target material with laser light,
A chamber;
A target generating unit that generates a target from the target material and outputs the generated target in a predetermined direction in the chamber;
A laser light source for generating the extreme ultraviolet light by irradiating the target in the chamber with a laser beam to form a plasma; and
A condensing mirror provided on the lower side of the target generator, for collecting the extreme ultraviolet light at a predetermined focal point;
The target generator is located below the output port for outputting the target, and is provided in the obscuration region of the condenser mirror, and the target output from the target generator is the condenser mirror A recovery unit for recovering the target so as not to adhere to
An extreme ultraviolet light source device.

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